The Preventive Intervention Research Center for Child Health (PIRC) is a clinically-based research center. It is dedicated to the development, implementation, and evaluation of preventive interventions designed to reduce the likelihood of mental health problems in children with serious ongoing physical health conditions and in their family members. During the next five years, we propose to build on the interdisciplinary work of the Center to date and to continue its programs in order to accomplish the following specific aims: 1) to expand our understanding of the relationship between physical and mental health among children with physical health conditions and their family members and to identify specific mechanisms through which this relationship can be altered; 2) to continue to design, implement, and evaluate preventive interventions that target high-risk children with a serious physical health condition and their family members; 3) to address systematically problems in the implementation of preventive interventions by developing broadly applicable methodologies, to guide a) the design and implementation of new interventions, and b) the adaptation of existing interventions to different settings, a populations, and problems; 4) to enhance the research training programs of the Center through development of post- doctoral training for social scientists who lack preventive intervention experience and for clinicians who lack social research and evaluation skills pertinent to prevention; 5) to continue to train preceptees by providing field experience in the design, implementation, conduct, and evaluation of preventive interventions in the field of mental health; 6) to expand the dissemination of new knowledge derived from our research results, intervention experience, and training curricula. In addition to continuing to build the Center's resources for interdisciplinary research, training, and dissemination in the field, we propose to conduct three new randomized controlled trials of preventive interventions that aim to promote successful developmental transitions and prevent psychological morbidity in high-risk groups of infants, children, and adolescents, and their mothers.